Postgres refactor.

postgres/select_statement.go

@@ -0,0 +1,144 @@
+package postgres
+
+import "github.com/go-jet/jet/internal/jet"
+
+type SelectLock = jet.SelectLock
+
+var (
+	UPDATE        = jet.NewSelectLock("UPDATE")
+	NO_KEY_UPDATE = jet.NewSelectLock("NO KEY UPDATE")
+	SHARE         = jet.NewSelectLock("SHARE")
+	KEY_SHARE     = jet.NewSelectLock("KEY SHARE")
+)
+
+type SelectStatement interface {
+	jet.Statement
+	jet.HasProjections
+	jet.IExpression
+
+	DISTINCT() SelectStatement
+	FROM(table ReadableTable) SelectStatement
+	WHERE(expression BoolExpression) SelectStatement
+	GROUP_BY(groupByClauses ...jet.GroupByClause) SelectStatement
+	HAVING(boolExpression BoolExpression) SelectStatement
+	ORDER_BY(orderByClauses ...jet.OrderByClause) SelectStatement
+	LIMIT(limit int64) SelectStatement
+	OFFSET(offset int64) SelectStatement
+	FOR(lock SelectLock) SelectStatement
+
+	UNION(rhs SelectStatement) SetStatement
+	UNION_ALL(rhs SelectStatement) SetStatement
+	INTERSECT(rhs SelectStatement) SetStatement
+	INTERSECT_ALL(rhs SelectStatement) SetStatement
+	EXCEPT(rhs SelectStatement) SetStatement
+	EXCEPT_ALL(rhs SelectStatement) SetStatement
+
+	AsTable(alias string) SelectTable
+}
+
+//SELECT creates new SelectStatement with list of projections
+func SELECT(projection jet.Projection, projections ...jet.Projection) SelectStatement {
+	return newSelectStatement(nil, append([]jet.Projection{projection}, projections...))
+}
+
+func newSelectStatement(table ReadableTable, projections []jet.Projection) SelectStatement {
+	newSelect := &selectStatementImpl{}
+	newSelect.ExpressionStatementImpl.StatementImpl = jet.NewStatementImpl(Dialect, jet.SelectStatementType, newSelect, &newSelect.Select,
+		&newSelect.From, &newSelect.Where, &newSelect.GroupBy, &newSelect.Having, &newSelect.OrderBy,
+		&newSelect.Limit, &newSelect.Offset, &newSelect.For)
+
+	newSelect.ExpressionStatementImpl.ExpressionInterfaceImpl.Parent = newSelect
+
+	newSelect.Select.Projections = projections
+	newSelect.From.Table = table
+	newSelect.Limit.Count = -1
+	newSelect.Offset.Count = -1
+
+	newSelect.setOperatorsImpl.parent = newSelect
+
+	return newSelect
+}
+
+type selectStatementImpl struct {
+	jet.ExpressionStatementImpl
+	setOperatorsImpl
+
+	Select  jet.ClauseSelect
+	From    jet.ClauseFrom
+	Where   jet.ClauseWhere
+	GroupBy jet.ClauseGroupBy
+	Having  jet.ClauseHaving
+	OrderBy jet.ClauseOrderBy
+	Limit   jet.ClauseLimit
+	Offset  jet.ClauseOffset
+	For     jet.ClauseFor
+}
+
+func (s *selectStatementImpl) DISTINCT() SelectStatement {
+	s.Select.Distinct = true
+	return s
+}
+
+func (s *selectStatementImpl) FROM(table ReadableTable) SelectStatement {
+	s.From.Table = table
+	return s
+}
+
+func (s *selectStatementImpl) WHERE(condition BoolExpression) SelectStatement {
+	s.Where.Condition = condition
+	return s
+}
+
+func (s *selectStatementImpl) GROUP_BY(groupByClauses ...jet.GroupByClause) SelectStatement {
+	s.GroupBy.List = groupByClauses
+	return s
+}
+
+func (s *selectStatementImpl) HAVING(boolExpression BoolExpression) SelectStatement {
+	s.Having.Condition = boolExpression
+	return s
+}
+
+func (s *selectStatementImpl) ORDER_BY(orderByClauses ...jet.OrderByClause) SelectStatement {
+	s.OrderBy.List = orderByClauses
+	return s
+}
+
+func (s *selectStatementImpl) LIMIT(limit int64) SelectStatement {
+	s.Limit.Count = limit
+	return s
+}
+
+func (s *selectStatementImpl) OFFSET(offset int64) SelectStatement {
+	s.Offset.Count = offset
+	return s
+}
+
+func (s *selectStatementImpl) FOR(lock SelectLock) SelectStatement {
+	s.For.Lock = lock
+	return s
+}
+
+func (s *selectStatementImpl) AsTable(alias string) SelectTable {
+	return newSelectTable(s, alias)
+}
+
+type SelectTable interface {
+	ReadableTable
+	jet.SelectTable
+}
+
+type selectTableImpl struct {
+	jet.SelectTableImpl2
+	readableTableInterfaceImpl
+}
+
+func newSelectTable(selectStmt jet.StatementWithProjections, alias string) SelectTable {
+	subQuery := &selectTableImpl{
+		SelectTableImpl2: jet.NewSelectTable(selectStmt, alias),
+	}
+
+	subQuery.readableTableInterfaceImpl.parent = subQuery
+
+	return subQuery
+}